Which Container Network Interface (CNI) is selected by default in a VMware Tanzu Kubernetes Grid...

Antrea is the default CNI for new Tanzu Kubernetes Grid workload clusters8. Antrea is an open-source Kubernetes networking solution that implements the Container Network Interface (CNI) specification and uses Open vSwitch (OVS) as the data plane9. Antrea supports various features such as network policies, service load balancing, NodePortLocal, IPsec encryption, IPv6 dual-stack, and more10.

The other options are incorrect because:

Multus CNI is an open-source container network interface plugin for Kubernetes that enables attaching multiple network interfaces to pods11. It is not the default CNI for Tanzu Kubernetes Grid workload clusters.

Flannel is an open-source simple and easy-to-use overlay network that satisfies the Kubernetes requirements12. It is not the default CNI for Tanzu Kubernetes Grid workload clusters.

Calico is an open-source network and network security solution for containers, virtual machines, and native host-based workloads13. It is not the default CNI for Tanzu Kubernetes Grid workload clusters.

References: Tanzu Kubernetes Grid Cluster Networking, Antrea, Antrea Features, Multus CNI, Flannel, Calico